1. Field of the Invention
The invention relates to a preparation of androstane 17-β carbothioic acid and relative compounds thereof, and in particular, to a preparation of androstane 17-β carbothioic acid without addition of hydrogen sulphide.
2. Description of the Related Art
Androstane compounds containing a carbothioate group in the 17β position have been found to possess anti-inflammatory properties. In particular such androstane compounds are disclosed in U.S. Pat. No. 4,650,610 filed by G. H. Philipps, B. M. Bain, C. Williamson, I. P. Steeples and S. B. Laing and U.S. Pat. No. 4,335,121 filed by G. H. Philipps.
However, the addition of a gaseous hydrogen sulphide, a toxic substance, is required for the conventional androstane preparation process, seriously affecting fabrication safety. Also, three or four preparation steps are required, making the preparation costly.